UC1901-SP

ACTIVE

Space-grade QMLV with isolated feedback generator

Product details

Vin (max) (V) 40 Operating temperature range (°C) -55 to 125 Rating Space Features 1% reference, Isolated feedback generator, Synchronizable
Vin (max) (V) 40 Operating temperature range (°C) -55 to 125 Rating Space Features 1% reference, Isolated feedback generator, Synchronizable
CDIP (J) 14 130.4652 mm² 19.56 x 6.67
  • An Amplitude-Modulation System for Transformer Coupling an Isolated Feedback Error Signal
  • Low-Cost Alternative to Optical Couplers
  • Internal 1% Reference and Error Amplifier
  • Internal Carrier Oscillator Usable to 5MHz
  • Modulator Synchronizable to an External Clock
  • Loop Status Monitor
  • An Amplitude-Modulation System for Transformer Coupling an Isolated Feedback Error Signal
  • Low-Cost Alternative to Optical Couplers
  • Internal 1% Reference and Error Amplifier
  • Internal Carrier Oscillator Usable to 5MHz
  • Modulator Synchronizable to an External Clock
  • Loop Status Monitor

The UC1901 family is designed to solve many of the problems associated with closing a feedback control loop across a voltage isolation boundary. As a stable and reliable alternative to an optical coupler, these devices feature an amplitude modulation system which allows a loop error signal to be coupled with a small RF transformer or capacitor.

The programmable, high-frequency oscillator within the UC1901 series permits the use of smaller, less expensive transformers which can readily be built to meet the isolation requirements of today's line-operated power systems. As an alternative to RF operation, the external clock input to these devices allows synchronization to a system clock or to the switching frequency of a SMPS.

An additional feature is a status monitoring circuit which provides an active-low output when the sensed error voltage is within ±10% of the reference. The DRIVERA output, DRIVERB output, and STATUS output are disabled until the input supply has reached a sufficient level to allow proper operation of the device.

Since these devices can also be used as a DC driver for optical couplers, the benefits of 4.5 to 40V supply operation, a 1% accurate reference, and a high gain general purpose amplifier offer advantages even though an AC system may not be desired.

The UC1901 family is designed to solve many of the problems associated with closing a feedback control loop across a voltage isolation boundary. As a stable and reliable alternative to an optical coupler, these devices feature an amplitude modulation system which allows a loop error signal to be coupled with a small RF transformer or capacitor.

The programmable, high-frequency oscillator within the UC1901 series permits the use of smaller, less expensive transformers which can readily be built to meet the isolation requirements of today's line-operated power systems. As an alternative to RF operation, the external clock input to these devices allows synchronization to a system clock or to the switching frequency of a SMPS.

An additional feature is a status monitoring circuit which provides an active-low output when the sensed error voltage is within ±10% of the reference. The DRIVERA output, DRIVERB output, and STATUS output are disabled until the input supply has reached a sufficient level to allow proper operation of the device.

Since these devices can also be used as a DC driver for optical couplers, the benefits of 4.5 to 40V supply operation, a 1% accurate reference, and a high gain general purpose amplifier offer advantages even though an AC system may not be desired.

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Design & development

For additional terms or required resources, click any title below to view the detail page where available.

Evaluation board

UC1843BEVM-CVAL — UC1843B-SP current mode PWM controller evaluation module

The UC1843BEVM-CVAL uses the UC1843A-SP, INA901-SP, LM139AQML-SP, and UC1901-SP to create an isolated feedback flyback with current sensing and over current flags. The UC1843A-SP is used to switch the low side MOSFET of the flyback converter and provide voltage and current to the output. The (...)
User guide: PDF
Not available on TI.com
Simulation model

UCx901 Family PSpice Average Model

SLUM063.ZIP (88 KB) - PSpice Model
Simulation model

UCx901 Family TINA-TI Average Reference Design

SLUM058.TSC (1026 KB) - TINA-TI Reference Design
Simulation model

UCx901 Family TINA-TI Average Spice Model

SLUM059.ZIP (7 KB) - TINA-TI Spice Model
Reference designs

TIDA-070002 — 20- to 40-VIN, 50-W Space-grade isolated flyback DC/DC over-current protection reference design

Spacecraft bus voltages vary from the well-established 28-V to more than the 100-V typically used in highpower commercial communications satellites, this reference design shows an example for a space-grade 50-W isolated intermediary bus converter, while implementing over-current protection (OCP) (...)
Design guide: PDF
Schematic: PDF
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CDIP (J) 14 Ultra Librarian

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